Objective: This study was planned to investigate whether or not troponin-T positivity has occurred during exercise stress testing in patients with stable angina pectoris and if yes, its relationship with the severity of the disease. Methods: One hundred patients with stable angina pectoris who presented with typical chest pain were included in this study. They were subjected to the exercise stress testing according to Bruce protocol. Troponin-T was studied 3 times: immediately before, 6 and 24 hours after the exercise testing. Coronary angiography was performed two hours after the last blood sampling. Results: Exercise stress test was found positive in 67 (67%) and negative in 33 (33%) patients. Coronary artery disease was present in 47 (70.1%) of those with positive and in 17 (51.5%) with negative test results. Troponin-T was negative in all the patients before the stress test. Troponin-T was found positive in readings taken 6 and 24 hours after the test in 4 patients (6.2%) with coronary artery disease. Of these patients, 2 had positive and the remaining 2 had negative stress test results. Troponin-T was found negative in readings after the stress test in all the patients without coronary artery disease. The duration of the exercise stress test was found to be significantly shorter in patients with troponin positivity than their counterparts with negativity (277.5±81 sec vs. 428.8±195 sec, p=0.024). Troponin-T positivity after the stress test was found considerably higher in patients with three-vessel disease (p=0.021). Conclusions: Heavy exercises like stress test may severely lead to myocardial damage. The study of post-stress test troponin T readings, in patients with stable angina pectoris and with negative stress test result, may be of great help in detecting especially the patients with multiple vessel disease.